【摘要】 提出一种基于混沌密钥的小波数字水印方法。该方法在现有的混沌数字水印系统基础上 ,增加一个混沌映射作为私有密钥来克服有限字长效应和提高算法的抗破译性。嵌入水印时 ,将原始图像进行四层小波分解 ,利用人类视觉系统 (HVS)特性 ,选择中频系数与混沌水印序列相加 ,进行取模运算后再嵌入到混沌映射模型中进行迭代。检测时 ,利用相应的混沌映射模型生成混沌水印序列 ,并与原始水印序列进行相关检测。研究结果验证了本文方法的有效性 ,并证明能比单一混沌系统提供更好的抗破译性能更多还原

【Abstract】 A chaotic digital watermarking method based on the private key and wavelet transform is proposed. To overcome finite word length effects and improve its resistance to the attack of crypt analysis, a chaotic map as a private key is added to the existing chaotic watermarking systems. The chaotic signal is embedded into the selected middle-frequency DWT coefficients on the basis, of the human visual system. At the same time take a modular operation on the sum and embed the result of the modular operation in the iteration of the chaotic generating systems. The chaotic sequence is retrieved from the watermarking image by using the corresponding chaotic model in the correlative detector. The simulation results show that the performance of this proposed watermarking system is of better security than that of the single chaotic map watermarking systems.更多还原